Mechanical arm and wafer cleaning device

Abstract

The utility model discloses a mechanical arm and a wafer cleaning device. The mechanical arm comprises a first arm, a purging gas channel and at least one purging opening, the first arm comprises a connecting end and an executing end, and the executing end comprises a bearing surface and is used for bearing a first wafer; the purging gas channel extends from the connecting end to the executing end, and at least one purging opening is located in the side, away from the bearing face, of the executing end and communicates with the purging gas channel. According to the mechanical arm, the blowing gas channel is additionally arranged on the first arm, and the back face of the bearing face is provided with the at least one blowing opening through which the gas flows out, so that in the process that the first arm takes and places the stacked wafers, the lower wafers are blown when the upper wafers are taken and placed, the removal effect of particle pollutants on the surfaces of the wafers is improved, and the service life of the wafers is prolonged. Lattice defects caused by particulate pollutants are reduced, and the yield of wafer processing is improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a robotic arm and a wafer cleaning device. Background Art

[0002] At present, filters are set in the atmospheric transmission unit to maintain the internal environment clean, and the wafers in the atmospheric transmission unit are cleaned by forming a top-down airflow. However, it is difficult for the filter to filter out all the particles of the external air intake, and it is inevitable that a small amount of particles will be deposited on the surface of the wafer with the top-down airflow. At the same time, because the wafer is transported horizontally, the airflow will diverge after reaching the surface of the wafer, resulting in poor cleaning effect. Utility Model Content

[0003] The utility model discloses a mechanical arm and a wafer cleaning device, which are used for blowing away particle pollutants on the surface of a wafer at a close distance, reducing lattice defects caused thereby and improving the yield rate of wafer processing.

[0004] In order to achieve the above object, the utility model provides the following technical solutions:

[0005] A robotic arm, the robotic arm comprising a first arm, a purge gas channel and at least one purge port;

[0006] The first arm includes a connecting end and an executing end, and the executing end includes a carrying surface for carrying a wafer; the purge gas channel extends from the connecting end to the executing end, and at least one purge port is located on a side of the executing end away from the carrying surface and is connected to the purge gas channel.

[0007] The above-mentioned robot arm is provided with a purge gas channel on the first arm, and at least one purge port for gas flow out is provided on the back of the bearing surface, so that the first arm can purge the lower wafer when the upper wafer is placed during the process of taking and placing the stacked wafers, thereby improving the removal effect of particle contaminants on the wafer surface. Specifically, the robot arm includes a first arm for taking and placing the wafers, and the wafers include a first wafer and a second wafer, and the first wafer is stacked above the second wafer. The first arm includes a connecting end and an executing end, the connecting end is transmission-connected to the base of the robot arm, and the executing end is a free end, including a bearing surface, for carrying the first wafer. The robot arm also includes a purge gas channel extending from the connecting end to the executing end, and a purge port connected to the purge gas channel. Among them, the purge gas channel can be parallel to the extension direction of the first arm, can also be at a certain angle to the extension direction of the first arm, or can be arranged in a curved shape; at least one purge port is connected to the tail end of the purge gas channel, and the opening faces the second wafer. With such an arrangement, when the first arm takes and places the first chip, the gas in the purge gas channel flows out from the purge port, thereby closely purging the second chip below the first chip, so as to better remove the particulate contaminants on the surface of the second chip, improve the cleaning effect, reduce the lattice defects caused by the particulate contaminants, and improve the yield of chip processing.

[0008] In some embodiments, the purge gas channel is embedded in the first arm; and at least one of the purge ports is disposed on a surface of the execution end facing away from the bearing surface.

[0009] In some embodiments, the robotic arm includes an air pipe, the purge gas channel is formed inside the air pipe, the air pipe is arranged on the side of the first arm away from the carrying surface, and at least one purge port is arranged on the surface of the air pipe away from the carrying surface.

[0010] In some embodiments, the execution end includes a first free end and a second free end opposite to each other, and each of the first free end and the second free end is provided with at least one purge port.

[0011] In some embodiments, the first arm is further provided with a laser sensor, a signal processor and a control valve;

[0012] The control valve is arranged on the purge gas channel and is used to control the gas flow rate of the purge gas channel;

[0013] The laser sensor is used to emit laser signals and receive reflected laser signals;

[0014] The signal processor is signal-connected to both the laser sensor and the control valve.

[0015] In some embodiments, the laser sensor is embedded in the first arm, and a working window adapted to the laser sensor is provided on the surface of the first arm facing away from the carrying surface; or, the laser sensor is provided on the surface of the first arm facing away from the carrying surface.

[0016] In some embodiments, the signal processor is embedded in the connecting end of the first arm.

[0017] In some embodiments, the robotic arm further includes a driving mechanism, which is transmission-connected to the connecting end of the first arm for controlling the movement of the first arm.

[0018] The utility model also provides a wafer cleaning device, comprising a central processing unit, an air source, a cleaning chamber and the mechanical arm;

[0019] The interior of the cleaning chamber is used to accommodate wafers; the cleaning chamber comprises an execution window and an exhaust port, wherein the execution window is arranged at the side of the cleaning chamber, and is used to allow the first arm of the robot arm to enter and exit to take and place the wafer; the exhaust port is arranged at the bottom of the cleaning chamber, and is used to discharge particulate contaminants;

[0020] The gas source is connected to the purge gas channel of the robotic arm; the central processing unit is signal-connected to the gas source and the control valve of the first arm.

[0021] In some embodiments, the central processing unit is configured to control the gas flow into the purge gas channel when the wafer is detected under the first arm, and control the gas flow rate of the purge port so that the pressure range of the gas at the purge port of the first arm is 0.08MPa-0.12MPa. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the structure of a mechanical arm provided by an embodiment of the utility model;

[0023] Figure 2 A schematic diagram of the structure of a robotic arm and a cleaning room provided in an embodiment of the utility model;

[0024] Figure 3 A schematic diagram of a partial structure of a mechanical arm provided in an embodiment of the utility model;

[0025] Figure 4 A schematic diagram of a partial structure of a mechanical arm provided in an embodiment of the utility model;

[0026] Figure 5 A schematic diagram of the structure of a mechanical arm provided by an embodiment of the utility model;

[0027] Figure 6 A schematic diagram of the structure of a mechanical arm provided by an embodiment of the utility model;

[0028] Figure 7 A schematic structural diagram of a wafer cleaning device provided by an embodiment of the utility model;

[0029] Icons: 1-first arm; 2-purge gas channel; 3-purge port; 4-air pipe; 5-laser sensor; 6-signal processor; 7-control valve; 8-central processing unit; 9-gas source; 10-cleaning room; 11-carrying surface; 12-first free end; 13-second free end; 101-execution window; 102-exhaust port; 100-first chip; 200-second chip. DETAILED DESCRIPTION

[0030] First, let me introduce the application scenario. In the semiconductor manufacturing process, the wafer to be processed needs to be gradually transferred from the atmospheric environment to the reaction chamber for process treatment. The process of transferring the wafer to the reaction chamber requires a wafer transfer system composed of a series of equipment to complete. The wafer transfer system includes an atmospheric transfer unit (Equipment Front-End Module, referred to as EFEM) and a transfer chamber connected to the atmospheric transfer unit. The atmospheric transfer unit takes the wafer out of the wafer box and transfers it to the transfer chamber. The transfer chamber transfers the wafer to the process chamber, and the process chamber processes the wafer; then the transfer chamber returns the processed wafer to the atmospheric transfer unit, and the atmospheric transfer unit transfers the processed wafer back to the wafer box.

[0031] Robotic arms are widely used in atmospheric transmission units. After the wafer is processed in the process chamber, there may be residual byproducts on the surface and tiny particles generated during the transmission of mechanical moving parts. These residues and particles attached to the surface of the wafer will contaminate the wafer, increasing the possibility of defects in the wafer causing failure. In order to solve the problem of particle contaminants attached to the surface of the wafer, a filter (Fan Filter Unit, FFU for short) is currently set on the top of the atmospheric transmission unit to filter out particles outside the atmospheric transmission unit and blow uniform gas downward. The gas eventually flows out from the bottom of the atmospheric transmission unit, thereby forming a top-down airflow inside the atmospheric transmission unit and generating a positive pressure slightly greater than the atmospheric pressure in the atmospheric transmission unit.

[0032] The filter inhales filtered air from the outside to generate a weak airflow from top to bottom to purge the wafer to remove byproducts and particles attached to the wafer surface. However, since the wafer is transported horizontally in the atmospheric transmission unit, and it is difficult for the filter to filter out all particles in the air inhaled from the outside, it is inevitable that a very small amount of particles will be deposited on the wafer surface with the top-down airflow. In addition, the airflow will diffuse after reaching the wafer surface. The diffused airflow makes it difficult for byproducts and particles in the central area of ​​the wafer surface to be blown away, which will reduce the effect of removing byproducts and particles on the wafer surface. Since the main function of the filter is to maintain the positive pressure of the atmospheric transmission unit and ensure the cleanliness of the internal environment, its ability to clean the wafer surface is limited.

[0033] Based on the above problems, an embodiment of the present application provides a robotic arm and a wafer cleaning device, which are used to blow away particulate contaminants on the wafer surface at a close distance, reduce the lattice defects caused thereby, and improve the yield of wafer processing.

[0034] The following will combine the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model. Among them, in the description of the embodiments of the present application, unless otherwise specified, " / " means or, for example, A / B can mean A or B; "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, "multiple" refers to two or more than two.

[0035] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0036] like Figures 1 to 6 As shown, in a first aspect, an embodiment of the utility model provides a mechanical arm, the mechanical arm comprises a first arm 1, a purge gas channel 2 and at least one purge port 3;

[0037] The first arm 1 includes a connecting end and an executing end, the executing end includes a carrying surface 11 for carrying a wafer; a purge gas channel 2 extends from the connecting end to the executing end, and at least one purge port 3 is located on the side of the executing end away from the carrying surface 11 and is connected to the purge gas channel 2.

[0038] The above-mentioned robot arm adds a purge gas channel 2 on the first arm 1, and sets at least one purge port 3 for gas outflow on the back of the bearing surface 11 of the first arm 1, so that the first arm 1 can purge the lower wafer when picking up and placing the upper wafer in the process of stacking wafers, thereby improving the removal effect of particle contaminants on the wafer surface. Specifically, Figure 1 and Figure 2 As shown, the robot arm includes a first arm 1 for picking up and placing wafers, and the wafers include a first wafer 100 and a second wafer 200, and the first wafer 100 is stacked on the second wafer 200. The first arm 1 includes a connecting end and an executing end, the connecting end is transmission-connected to the base of the robot arm, and the executing end is a free end, including a bearing surface 11, for carrying the first wafer 100. The robot arm also includes a purge gas channel 2 extending from the connecting end to the executing end, and a purge port 3 connected to the purge gas channel 2. Among them, the purge gas channel 2 can be parallel to the extension direction of the first arm 1, or it can be at a certain angle to the extension direction of the first arm 1, or it can be arranged in a curved shape; at least one purge port 3 is connected to the tail end of the purge gas channel 2, and the opening faces the second wafer 200. With such an arrangement, when the first arm 1 takes and places the first chip 100, the gas in the purge gas channel 2 flows out from the purge port 3, thereby closely purging the second chip 200 below the first chip 100, so as to better remove the particulate contaminants on the surface of the second chip 200, improve the cleaning effect, reduce the lattice defects caused by the particulate contaminants, and improve the yield of chip processing.

[0039] It should be noted that the robotic arm also includes a second arm, a third arm, a fourth arm and other components connecting the first arm 1 and the base, and the first arm 1, the second arm, the third arm and the fourth arm are connected by transmission. The first arm 1 is an execution component for picking up and placing chips, and the second arm, the third arm and the fourth arm are used to transmit power to the first arm 1 so that the first arm 1 reaches the position for picking up and placing chips.

[0040] In some embodiments, the purge gas channel 2 is embedded in the first arm 1 ; and at least one purge port 3 is disposed on a surface of the execution end facing away from the carrying surface 11 .

[0041] One possible way to achieve this is as follows: Figure 1As shown, the purge gas channel 2 is arranged inside the first arm and extends from the connecting end to the execution end. The purge port 3 is arranged on the side surface of the execution end of the first arm 1 away from the bearing surface 11, and the purge port 3 is connected to the tail of the purge gas channel 2. When the externally connected gas passes through the purge gas channel 2 and is ejected from the purge port 3, it acts on the second wafer 200 under the first arm 1, and the particulate contaminants on the wafer surface can be removed at a close distance to improve the cleaning effect. It should be noted that the number of the purge ports 3 can be 1, 2, 3, etc., and there is no specific limitation.

[0042] In some embodiments, the robotic arm includes an air pipe 4 with a purge gas channel 2 formed inside. The air pipe 4 is arranged on the side of the first arm 1 away from the bearing surface 11, and at least one purge port 3 is arranged on the surface of the air pipe 4 away from the bearing surface 11.

[0043] One possible way to achieve this is as follows: Figure 3 As shown, the robot arm includes an air pipe 4, which can be fixedly installed on the side of the first arm 1 away from the bearing surface 11 by bonding or clamping. A purge port 3 is opened at the end of the air pipe 4 away from the first arm 1. External gas can reach the purge port 3 through the purge gas channel 2 formed inside the air pipe 4. After the gas flows out of the purge port 3, it acts on the second wafer 200 under the first arm 1 to remove particulate contaminants. Similarly, the number of purge ports 3 can be 1, 2, 3, etc., and is not specifically limited.

[0044] Another possible implementation method is Figure 4 As shown, the side of the first arm 1 away from the bearing surface 11 can also be set as a groove to accommodate the air pipe 4. The air pipe is installed inside the groove to prevent the first arm 1 from damaging the second chip 200 below when taking and placing the first chip 100.

[0045] In some embodiments, the execution end includes a first free end 12 and a second free end 13 opposite to each other, and each of the first free end 12 and the second free end 13 is provided with at least one purge port 3 .

[0046] One possible way to achieve this is as follows: Figure 5 As shown, the execution end is a U-shaped structure with an opening facing away from the connection end. The execution end of the first arm 1 includes a first free end 12 and a second free end 13. The first free end 13 and the second free end 13 are both provided with at least one purge port 3 facing away from the bearing surface 11. The purge gas channel 2 is connected to the purge ports 3 on the first free end 13 and the second free end 13, respectively. Such a configuration allows more gas to act on the second wafer 200, and the gas output is more uniform, resulting in a better cleaning effect. Similarly, the number of purge ports 3 can be 2, 3, 4, etc., and is not specifically limited.

[0047] In some embodiments, the first arm 1 is further provided with a laser sensor 5, a signal processor 6 and a control valve 7;

[0048] The control valve 7 is provided on the purge gas channel 2 and is used to control the gas flow rate of the purge gas channel 2;

[0049] The laser sensor 5 is used to emit laser signals and receive reflected laser signals;

[0050] The signal processor 6 is signal-connected to both the laser sensor 5 and the control valve 7 .

[0051] One possible way to achieve this is as follows: Figure 6 As shown, when the first arm 1 takes and places the first wafer 100, the laser sensor 5 emits a laser signal in the direction of the second wafer 200 and receives a reflected laser signal. The received reflected laser signal is compared with the preset laser signal in the data packet of the signal processor 6 to determine whether the second wafer 200 exists. The signal processor 6 is signal-connected to the laser sensor 5 and the control valve 7. When the second wafer 200 is detected, the control valve 7 will be opened, and the gas will reach the purge port 3 through the purge gas channel 2, acting on the second wafer 200 to clean the wafer; when the second wafer 200 is detected to be absent, the control valve 7 will remain closed, and no gas will flow out, thereby avoiding waste of gas.

[0052] In some embodiments, the laser sensor 5 is embedded in the first arm 1 , and a working window adapted to the laser sensor 5 is provided on the surface of the first arm 1 facing away from the carrying surface 11 ; alternatively, the laser sensor 5 is provided on the surface of the first arm 1 facing away from the carrying surface 11 .

[0053] In one possible implementation, the laser sensor 5 may be disposed on a surface of the first arm 1 that is away from the carrying surface 11 , so as to emit a laser signal to the second wafer 200 without obstruction and receive a reflected laser signal.

[0054] In another possible implementation, the laser sensor 5 can also be arranged inside the first arm 1. In this case, a working window (not shown in the figure) matching the laser sensor 5 should be provided on the surface of the first arm 1 facing away from the carrying surface 11, so that the emitted laser signal can reach the second wafer 200 through the working window. At the same time, the embedded design can prevent the first arm 1 from damaging the second wafer 200 below when taking and placing the first wafer 100.

[0055] In some embodiments, the signal processor 6 is embedded in the connection end of the first arm 1 .

[0056] In one possible implementation, the signal processor 6 is disposed inside the connection end of the first arm 1 to ensure that the bearing surface 11 of the first arm 1 has a flat working surface, which is convenient for taking and placing the first wafer 100. It should be noted that the signal processor can also be disposed on the upper part of the connection end, and the specific position is not limited.

[0057] In some embodiments, the robotic arm further includes a driving mechanism (not shown in the figure), which is transmission-connected to the connecting end of the first arm 1 for controlling the movement of the first arm 1 .

[0058] In one possible implementation, the robotic arm also includes a driving mechanism for moving the first arm 1 in space to control the movement and stop of the first arm 1, so as to facilitate the placement of the first chip 100 and to achieve the purging of the second chip 200 after moving into position.

[0059] Second, as Figure 7 As shown, the utility model also provides a wafer cleaning device, including a central processing unit 8, an air source 9, a cleaning chamber 10 and a mechanical arm;

[0060] The interior of the cleaning room 10 is used to accommodate wafers; the cleaning room 10 includes an execution window 101 and an exhaust port 102. The execution window 101 is provided at the side of the cleaning room 10 to allow the first arm 1 of the robot arm to enter and exit to take and place the wafer; the exhaust port 102 is provided at the bottom of the cleaning room 10 to discharge particulate contaminants;

[0061] The gas source 9 is connected to the purge gas channel 2 of the robotic arm; the central processing unit 8 is signal-connected to the gas source 9 and the control valve 7 of the first arm 1 .

[0062] In some embodiments, the central processor 8 is configured to control the gas flow into the purge gas channel 2 when a wafer is detected under the first arm 1, and control the gas flow rate of the purge port 3 of the first arm 1 so that the gas pressure range of the purge port 3 is 0.08MPa-0.12MPa.

[0063] One possible way to achieve this is as follows: Figure 7As shown, the first arm 1 of the robot arm enters the cleaning room 10 through the execution window 101 and moves to the bottom of the first wafer 100. When the driving mechanism controls the first arm 1 to reach the working position, the first arm 1 will receive the position signal sent by the central processor 8 to stop the first arm 1 from moving. It should be noted that the central processor 8 is signal-connected to the laser sensor 5 and the signal processor 6. When the first arm 1 stops moving, the central processor 8 controls the laser sensor 5 to emit a signal and controls the signal processor 6 to compare the signal. When the second wafer 200 is detected, the control valve 7 of the purge gas channel 2 receives the signal of the central processor 8 and opens, and then the gas flows out through the purge gas channel 2, and finally acts on the second wafer 200, blowing away the byproducts remaining on the surface of the second wafer 200 after processing, the particles that are not completely filtered out by the filter in the cleaning room 10, and the particles generated by the movement of the robot arm as much as possible. The particles are finally brought into the exhaust port 10 at the bottom of the cleaning room 10 through the top-down airflow in the cleaning room 10 and sent to the factory waste gas treatment system for centralized treatment. When the second wafer 200 is not detected, the control valve 7 remains closed.

[0064] It should be noted that the gas source can be a high-purity nitrogen PN2 plant supply terminal. The clean room 10 can be a cooling station, a buffer station, an airlock room, or other area with an exhaust device. The exhaust port 10 is connected to the plant negative pressure pipeline so that the particulate pollutants can be discharged smoothly.

[0065] It is understandable that the gas pressure setting should be within a reasonable range. Too low a pressure will result in poor cleaning effect, and the particle contaminants on the surface of the second wafer 200 cannot be purged clean. Too high a pressure will easily blow the second wafer 200 off-center, and there is a risk of the wafer slipping when the second wafer 200 is placed. Therefore, the gas pressure range should be set between 0.08MPa and 0.12MPa. Exemplarily, the gas pressure is 0.08MPa, 0.09MPa, 0.10MPa, 0.11MPa, 0.12MPa, etc. When the gas pressure is set to 0.10Mpa, better purging and cleaning effects can be achieved under this pressure.

[0066] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A robotic arm, characterized in that: The robotic arm includes a first arm, a purge gas channel and at least one purge port; The first arm includes a connecting end and an executing end, and the executing end includes a carrying surface for carrying a wafer; the purge gas channel extends from the connecting end to the executing end, and at least one purge port is located on a side of the executing end away from the carrying surface and is connected to the purge gas channel.

2. The robotic arm according to claim 1, characterized in that: The purge gas channel is embedded in the first arm, and at least one of the purge ports is disposed on a surface of the execution end facing away from the bearing surface.

3. The robotic arm according to claim 1, characterized in that: The robot arm includes an air pipe, the purge gas channel is formed inside the air pipe, the air pipe is arranged on the side of the first arm away from the bearing surface, and at least one purge port is arranged on the surface of the air pipe away from the bearing surface.

4. The robotic arm according to claim 1, characterized in that: The execution end includes a first free end and a second free end that are opposite to each other, and each of the first free end and the second free end is provided with at least one purge port.

5. The robotic arm according to any one of claims 1 to 4, characterized in that: The first arm is also provided with a laser sensor, a signal processor and a control valve; The control valve is arranged on the purge gas channel and is used to control the gas flow rate of the purge gas channel; The laser sensor is used to emit laser signals and receive reflected laser signals; The signal processor is signal-connected to both the laser sensor and the control valve.

6. The robotic arm according to claim 5, characterized in that: The laser sensor is embedded in the first arm, and a working window adapted to the laser sensor is provided on a surface of the first arm facing away from the carrying surface; or, the laser sensor is provided on a surface of the first arm facing away from the carrying surface.

7. The robotic arm according to claim 6, characterized in that: The signal processor is embedded in the connecting end of the first arm.

8. The robotic arm according to claim 1, characterized in that: The robotic arm also includes a driving mechanism, which is transmission-connected to the connecting end of the first arm and is used to control the movement of the first arm.

9. A wafer cleaning device, characterized in that: It comprises a central processing unit, an air source, a cleaning chamber and a robotic arm as claimed in any one of claims 1 to 8; The interior of the cleaning room is used to accommodate wafers; the cleaning room includes an execution window and an exhaust port, and the execution window is arranged on the side of the cleaning room to allow the first arm of the robot arm to enter and exit to take and place the wafer; The exhaust port is arranged at the bottom of the cleaning chamber and is used to discharge particulate pollutants; The gas source is connected to the purge gas channel of the robotic arm; the central processing unit is signal-connected to the gas source and the control valve of the first arm.

10. The wafer cleaning device according to claim 9, characterized in that: The central processing unit is configured to control the gas flow into the purge gas channel when the wafer is detected under the first arm, and to control the gas flow rate of the purge port of the first arm so that the gas pressure range of the purge port is 0.08MPa-0.12MPa.

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